proton meaning
EN
[ˈprəʊ.tɒn] [ˈproʊ.tɑːn] WProton
- The proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and mass slightly less than that of a neutron.
- In the modern Standard Model of particle physics, the proton is a hadron, and like the neutron, the other nucleon (particle present in atomic nuclei), is composed of three quarks.
- At sufficiently low temperatures, free protons will bind to electrons. However, the character of such bound protons does not change, and they remain protons.
FR proton 
- NounPLprotonsPREproto-SUF-ton
- (physics) positively charged subatomic particle forming part of the nucleus of an atom and determining the atomic number of an element; the nucleus of the most common isotope of hydrogen; composed of two up quarks and a down quark.
- (physics) positively charged subatomic particle forming part of the nucleus of an atom and determining the atomic number of an element; the nucleus of the most common isotope of hydrogen; composed of two up quarks and a down quark.
- More Examples
- Used in the Middle of Sentence
- Following the synthesis of acetylcholine, acetylcholine generated in neurons is antiported by protons into secretory vesicles using vesicular acetylcholine transporter (VAChT).
- Used in the Middle of Sentence
Definition of proton in English Dictionary
- Part-of-Speech Hierarchy
- Nouns
- Countable nouns
- Countable nouns
- Nouns
Source: Wiktionary
Grammatically, this word "proton" is a noun, more specifically, a countable noun.